Process of tanning hides



(No'Model.) L. SOHN-ADEL.

PROCESS OP TANNING HIDES.

No. 293,364..v atented Feb. 12,`]l884.

' hide-mill for one-half hour.

IJNiTnD STATES' PATENT Orman..

LOUIS SOHNADEL, OF CHICAGO, ILLINOIS.

PRocr-:ss oF'TANNmci-lloes. 4

SPECIFICATION forming part of Letters Patent No. 293,364, datedFebruarylZ, 1884.

Application led June 23, 1883. (Nomiodel.)

My object is to lessen the bark used, and

produce a better leather in less time, and add more weight to it.

The accompanying drawing shows the internal arrangement of a tannery.

The vats, markedAareleaching-vats; B, layer-vats; C, lime-vats; D,bedmill; E, color-mill; F,hidemill; G, receiving-tank for distributing the liquor after being used; I-I, soaking-vats.

The first operation is to put the hides into freshwater for five or six hours, then into the The hide-mill is a vat having a long wheel with-open buckets that, as it revolves, stirs up the hides; then into fresh water-in the summer, thirty-four hours, in the winter, thirty-six hours; then back into the hiden1illonehalf hour. After this operation all the superiiuous flesh is taken off by the ordinary means. It is then put into the several lime-vats and changed from one to another until the hide has been into ve 1ime-vats. The lime-water in the iirst vat must be 25 in strength, and the hide remains Y therein one day. It is then changed into the second vat, the limawater being 26, and re-` mains one day. It is then changed into the third vat, the lime-water being 28, for one day; then into the fourth vat, the linie-water being 32, for one day; then into the fifth vat,

e the lime-water being 35, for one day. If any change is made in these several periods of time, the lime water must be changed in strength in the same proportion. The hide is then put into a sixth vat of pure water. This is followed up until three several packs have passed through the several vats. By this time a large quantity of lime has been deposited in the fresh-water vat. I then draw out the exhausted lime-water in No. 1 and add to No. 6 one barrel of lime, and ll No. 1 with fresh water, and then follow that up with three more packs of hides in the same manner. By thus going around continuously I make and keep the lime water of a right degree of strength, and economize the lime. The -water must be kept at in the summer and .80 in the winter. The hide is then washed in the hide-1nill until the lime is entirely cleaned Off.

one-half bushel to one hundred heavy hides;

one bushel to a hundred light sides; threefourths bushel to one hundred light kips; onehalf bushel for two hundred calf.

The bed-mill is similar in construction to the hide-niill-that is, the vat has a revolving wheel in it to agitate the hides. The mill is run five hours and the hide remains in twelve hours ,after the stoppage of the wheel. The hide is then put into the hide-mill and washed clean in cool water. It is then soaked in temperately warm water about one to two hours. Then the fine hair is taken-off. Itis then put into the color-mill, the liquor of which is made of hemlock or oak bark and water, and must be 4 to 5 of strength. The hide is left in three hours, and stirred by a moving wheel therein or otherwise. Then it is taken out and put into the handling-vats. lThe operation there is to change it from one to the other until it has passed through six vats, remaining a day in each, 'the liquor of each one increasing one-fourth of a degree in strength up to the last vat. It is then put into the layer-vats, which consist of a layer of hides and a layer of fine bark in as many layers as required, and changed from one to another until it has been in five successive vats, having the liquor in the following degrees or" strength and remaining the following lengths of time: in the rst layer-vat three days, liquor 8 to 9; then into vat No. 2, six days, liquor 10- to 11; No. 3 vat, nine days, liquor 12 to 13; No. 4 vat, twelve days, liquor 14 to 15; No. 5 vat, {ifteen days, liquor 17 to 18. By this process the hide is gradually permeated by the liquor. The liquor of these vats must be especially prepared according to my plan, both to get good liquor andget all the strength out of the bark. The bark is ground into the several leaching-vats, made of wood, and in any desired shape and size, and six or more in number. I use six to a set, so that the process IOO hereinafter stated makes the entire revolution used in the layer-vats and tempered to suit f above stated the liquor as it passes through 1the fresh bark is filtered and strengthened.

the several layer-vats, as hereinbefore stated, then part of' the exhausted liquor of'the handling-vats is run into the color-mill, as much as is necessary to fill it. rlhe remainder of thelaquor in the handling-vatsis run over thesameleach: No. 1, and, being strengthened' and purifiedis run back into they handling`vats.l I can run \weak liquor over this leach from; the; storage.- vtank until time for steaming, which comes.

every sixv days, Whensix vatsareused," In the meantime leach No. 3A having been treated as No. 1 therewill be asmallpercentageo tannin left inthe bark. I nowsteam it and the residue is passed over into. the: next vat and. goes on with the other liquor,- getting cool beforebeing used'. This is of the greatest importance, as unless` it is cool it spots the hide; andY rots it. The saine processl is usedA in all of the several vais-that is, the bark ink No. 2, being treated and exhausted as No., 1 it is thrown out and lledWit-hfresh-ground bark, and While this is being run overby'exhausted liquor, as No. 1, No. 4 is ready for steaming, that vat having been, treated asl No. l, so that by filling and treating each as abovedescribed p I keep rotating the leaching and steam-ing in succession throughout any space of time, and by thus continuallyV using the liquor over and` Q ruiming it through fresh-ground bark it gains strength and is cleared of impurities deposited in it by hides having been through it. 'Ihis is the only means by Which hides can be treated Without a risk of spoiling. By the ordinary process large quantities of hides are lost in the tanneres of the country. 'Often Whole yards are lost by the liquor not being kept l"pure, whereas I can by the above-mentioned process keep the liquor pure and prevent that I loss.

It can easily be seen bythe several leachings By this process I am enabled to make a saving of forty per cent. of the bark, a desirable obect as that article is 0rowing scarce ever 7 ZD b year. I also make the leather in a shorter yspace of time andy add more Weight to a hide,

and produce abetter article, -and prevent any loss in the beam-house, Where great loss often takes place.

Vhat I claim, and am desirous of securing by Letters Patent, is-

The process of tanning hides consisting in, first, treating the hides in fresh Water and in the hide-mill; second, placing the hides inthe lime`vats untilV the coarser hair is taken off;

hidesA in a bed made of human excrenient or fowl-manure; fifth, Washing the hides clean; sixth, soaking them in Water until thefinehairy is taken off; seventh, placing the hides in a coloring-mill; eighth, then placing them yinhandling-vats; ninth, placing the hides in thelayervats, substantially as described.

. LOUIS SCHNADEL.

Witnesses.:

J As. LORENZO GAGE, Louis W. H. Nnnrv.'

third, Washing thehides; fourth, placing the 

